Solar heater



J. D. M CAIN SOLAR HEATER Filed Oct. 17, 1938 F/GZ.

[NV EN TGR.

A TTORNE Y Patented Oct. 21, 1941 UNITED STATESfPATENT OFFICE 2,250.09:soua mm John David min, Phoenix, Aria. Application October 11, ms,Serial No. team (or. ire-s11) scum.

My invention relates to solar heaters of the type adapted to collect therays of the sun and direct the concentrated rays to a focal point on anobject to be heated.

One of the objects of my invention is to provide such a device ofsimple, rugged construction character in whichadiustment of the focalpoint is not critical and in which adjustment may be made to allow forthe seasonal change in the apparent path of the sun easily and quickly.

A further object is to provide a device of this kind in which theconcentrating lens may be easily replaceable in case it becomes damagedin use: and

A further object is to provide a device of the character mentioned inwhich a lens of novel type is combined with apparatus for receiving theheat concentrated and converting same into a form of energy which may beeasily applied to useful work.

Other objects will appear hereinafter.

I attain the foregoing objects by means of the apparatus, device andmechanical constructions illustrated in the accompanying drawing inwhich Figure 1 is a side elevational view of my type of lens;

Figure 2, an end or edgewise view thereof;

Figure 3, a side elevation of the device adapted to utilize said lensfor the production of vapor from fluids, or the like, with certainportions thereof shown in section to better illustrate theirconstruction.

Similar numerals refer to similar parts in all views.

Considering first, the lens, attention is directed to Figures 1 and 2.The lens, or refractor, is made of cast and polished glass in thegeneral shape of a ring, a section of which is uniformly convex. Thusformed, I have provided a continuously annular convex lens adapted toconcentrate the suns rays striking its outer periphery within asemi-cylindrical focal area having an axis coinciding with that of thering.

In use, this lens is positioned with its axis at right angles to thePlane of the ecliptic; that is, so that its central diametric planecoincides with the ecliptic and the apparent path of the tioned, onlythe upper portion of the lens is used at any one time. It might bepresumed that it would be easier to construct an arcuate semicircularlens of this nature. However, I have found that it is more eflclent toconstruct a lens in circular form, as here illustrated. In this form itmay be easier cast and ground that would be the case with semi-circulararcuate segments. The diameter of the lens ring is such that, with agiven sectional convexity of the annular body of the lens, light will befocused within an area around the periphery of cylinder 8. As the sunmoves from horizon to horizon, the focused rays move in an annular path,as indicated by numeral 4, around the central portion of this cylinder.Concentration of light rays 3 is effected principally by the convexityof the section I of the ring but secondarily -by the annular convexshape of the ring body. Therefore, it may be said that the focal area ofthe lens body lies within an annular space surrounding the axis of thering 2. At any one time the point or area of concentrated light and heatis directed on one spot or portion of the surface of the generatorcylinder. As the sun moves, this place of concentration movesaccordingly around a selected portion of the cylinder. In order tomaintain an even focus, the axis of the cylinder, therefore, mustcoincide with the axis of the ring. Further, the radius of the ringmust. be proportioned so that, with a given (or predetermined) convexityof the ring section I, the focal area will lie approximately upon thesurface of the generator cylinder. The generator, of course, may have aspherical shape or a semi-cylindrical shape rather than that shown. Inall cases, however, it should have an annular surface, the axis of whichcoincides with the axis of the ring body. The position of this focalarea, as generated for the entire ring, is indicated by numeral 4.

It is to be understood that the sun's rays are not concentrated to afine point upon the surface of the generator within the focal area butonly sufficiently to obtain the degree of heat required. In someinstances, therefore, with a lens of the same proportions, a generatorhaving a.

larger, or another having a similar cylinder may be used. The focal areain such cases, wouldv have a greater or less diameter depending upon thesize of the generator cylinder, and broadly might be better termed as a.focal space surrounding the axis of the ring. The outer periphery of thering is indicated by numeral 5, the inner sun from horizon to horizon.when thus posi- P ip y y numeral 8 and the relative convexity of thesesurfaces-shown in section at I in Figure 3.

Anadaption of this type of lens to one form of device is illustrated inFigure 3. Here numeral 8 indicates a closed metallic cylinder which maybe termed a generator or boiler, having an outlet tube 8 at its upperand right hand and an inlet l axially positioned and extending from theright hand end into the body of the cylinder as indicated by dottedlinesii, to a position near the left hand end of the cylinder. This inlet orreturn pipe is provided with a check valve i2.

This cylinder is mounted on trunnions i4, supported in a yoke i5 nearits right hand end and on an axially extending rod It at its left handend. This rod is held by thumb adjusting nut and bolt I! in an arcuateslot [8 in the are shaped supporting bar IS. The lens 2 is positionedwith its axis coinciding with that of generator cylinder 8 and supportedon a frame 28 which, in turn, is supported on a sleeve 2| fitted aroundcylinder 8. This sleeve may have a comparatively loose fit around thecylinder and thus permit both longitudinal axial adjustment of the lensalong the body of cylinder 8 as well as circumferential rotary movementof the lens when desired.

In order to control the amount of heat applied to cylinder 8 at the areaof concentration 4, I have provided a cylindrical mask 22 of metal, orother suitable material, mounted on spokes 23 attached to a hub 24, andthis, in turn, mounted on cylinder -8 to provide a sliding fit so thatthe entire mask assembly may be easily moved longitudinally on thecylinder by control rod 25, which may be connected by levers and rods orcables to any position desired for remote control.

When thus set up, the device may be positioned so that the axis of thering is at right angles to the .plane of the ecliptic. The axis of thering is perpendicular to the dotted line EE, which represents a planebisecting the annular body of the ring. When the axis of the cylinderand ring is placed in a north and south position the plane E--E may bemade to coincide with the ecliptic by varying the position of rod 8 insupport l8. Thus the position of the lens may be adjusted to have thecorrect angular position necessary to maintain the proper focusaccording to the season. Liquid to be vaporized is then introduced intocylinder 8 through pipe Hi. This may be water which is desired to beconverted into steam for the purpose of operating a machine or it may beliquid containing gas such as Freon to be driven oif under pressure andused for obtaining refrigeration. In either case, after boiling orvaporization, due to the heat applied to cylinder 8, at the focal point,vapor escapes through the outlet pipe 8 and condensed liquid is returnedfrom a closed circuit through check valve I2 and inlet I 0, to the loweror left hand portion of cylinder 8.

aasaeoe When it is desired to reduce the action of the device while thesun is shining, a portion of the rays to be concentrated is cut ofl bymoving the mask 2: in thedirection indicated by the arrow 28. Thusregulation may be eflected.

Aside from the use above illustrated and described, the device may beused to heat a semihorizontal portion of vent pipe leading from a roomto be ventilated to the atmosphere. By heating a portion of this ventpipe with a lens of this type, a hot spot is created on the pipe. airtherewithin expanded, and a draft created; all without the necessity ofany moving parts whatever.

Other uses are readily apparent.

Having now described my invention and explained its uses, it will beapparent to those familiar with the art that the device is subject tonumerous changes and modifications, all of which, however, will remainwithin the spirit of the invention. Therefore, I wish to be bound onlyby the following claims:

I claim:

1. A solar heater comprising, in combination, an annular glass refractorlens having a convex section adapted to focus the suns rays on a focalarea within an annular space surrounding its axis of curvature andbetween said axis and the body of the lens, a generator adapted tocontain liquids to be vaporized comprising a closed vessel provided withoutlet and inlet connections positioned with a portion thereof withinthe focal area of said refractor lens, and means of support for saidrefractor lens and said generator,.whereby they may be adjusted tomaintain the axis of said lens substantially perpendicular to the planeof the ecliptic.

2. A solar heater comprising, in combination, a glass refractor lenshaving a ring-shaped annular body with a convex section adapted to focusthe suns rays on a focal area within an annular space surrounding itsaxis between said axis and the body of the lens, a generator adapted toevaporate liquids including a tubular container having an outlet pipe atits upper end, and an inlet pipe communicating with its lower end,adjustable means for supporting said refractor on said generator so thata predetermined portion of said generator lies within the focal area ofsaid refractor, means for adjustably supporting said refractor andgenerator to permit the central diametrical plane of said refractor tobe positioned to coincide with the Plane of the ecliptic throughoutseasonal variation and maintain the focal relation of said refractor andgenerator, and means for controlling the amount of heat at said focalarea, including adjustable masking means movable to a position betweensaid refractor and said focal area.-

JOHN DAVID MCCAIN.

